Our trees are large for apple trees, we have several others. Lots of fruit, just never anything edible; never get larger round than quarter
Apples do not reproduce true to type, meaning that the tree from the seed will produce apples that are almost certain to be different than the parent.
There's a very good chance the apples won't even be edible.
Seeds from your dwarf apple tree will often produce full-sized trees. Many of these dwarf trees sold are created by grafting the variety onto a dwarfing rootstock. The variety itself may have the full-size genes, so that is what will come out when crossed.
Also, apple trees from seed take longer to produce fruit. It usually takes about 7 to 10 years before you can even tell if you are lucky and have good fruit. Once in a while, lucky finds are accidentally discovered among trees grown from seeds, that can be the fun in growing apples from seeds.